The present invention relates to an input integrated flat panel display system with a good man-machine performance in which an input device and an output device are integrated and the user can input data in handwritten form which is suitable for unskilled or amateur end users not accustomed to keyboards.
Recently, rapid development has occurred in the business transaction field mainly with respect to such operations as a document processing and graphic or figure processing, office automation has progressed rapidly, and OA (Office Automation) apparatuses such as word processors and personal computers have been increasingly employed. Conventionally, in processing data handwritten characters of figures are inputted through an input device such as a digitizer called a "tablet" and the recognized results or handwritings are displayed on an input device, such as a CRT (Cathode Ray Tube) display and then subjected to various processings. With the system using such input and output devices independent from each other, the user must confirm the inputs of characters or figures written on the digitizer by looking on each input occasion at the CRT display. Also, in editing, it is necessary to observe the characters or figures written on the CRT display while operating upon the digitizer. Thus, the work efficiency of the conventional device is very low.
Also known is a system using a CRT as an output device and a light pen as an input device. This system, however, has serious problems, since the thickness between the surface of a CRT and its fluorescent screen is more than 10 mm, and so the problem of parallax is difficult to solve; in addition, the user's arms become fatigued to a large degree unless the environmental structures are modified.
Apparatuses solving the above problems and improving operational performances are known in: (1) an article entitled "ON-LINE HANDWRITTEN CHINESE CHARACTER RECOGNITION HAVING A TREND OF RELAXING RESTRICTIONS ON THE WAY OF HANDWRITING SUCH AS DEFORMED WRITING CHARACTERS" at pages 115 to 133, Vol. 12.5, 1983, of NIKKEI ELECTRONICS published by Nikkei-McGraw-Hill, Inc.; (2) Japanese Patent Laid-Open Publication No. SHO 49-123239 entitled "PICTURE IMAGE INPUT DEVICE"; (3) Japanese Patent Laid-Open Publication No. SHO 58-14247 entitled "COORDINATE INPUT DEVICE WITH DISPLAY"; (4) Japanese Patent Laid-Open Publication No. SHO 58-96382 entitled "HANDWRITTEN CHARACTER RECOGNITION AND DISPLAY DEVICE"; and (5) Japanese Patent Laid-Open Publication No. SHO 58-144287 entitled "HANDWRITING INPUT WORD PROCESSOR" wherein there is described a flat panel display having a transparent digitizer mounted on the upper face of a flat display (such as an LCD (Liquid Crystal Display), EL (Electro-Luminescent) or plasma display), the input device and the output (display) device being integrated.
The input/output integrated display uses as a display device a flat panel display unit such as a LCD. This is because the flat panel display unit is suitable for attaining an integrated structure. The following problems arise if a highly precise and fine display type CRT display is used as a display device for the input/output integrated display:
(1) The thickness of the glass on the CRT screen is about 2 cm, which results in a relatively long distance between the writing surface of the input plate and the display surface. Therefore, parallax exists and a special coordinate transformation is required for compensating the parallax.
(2) Since the distance between the writing surface and the display surface becomes long, the user obtains a different feeling from that of actual writing. Moreover the display contents on the display surface can not be correctly recognized, which might be subjected to change for example by the posture of the operator. A method to solve the above problems has been proposed by joint inventors of the present application in Japanese Patent Laid-Open Publication No. SHO 59-183428 laid open Oct. 18, 1984 and entitled "METHOD OF INPUT-OUTPUT COORDINATE TRANSFORMATION FOR INPUT INTEGRATED DISPLAY DEVICE" but this reference is not prior art.
A display device such as an LCD for use with an input/output integrated flat panel display, however, has two technical problems as compared with a CRT display: (1) there are some restrictions on the display area, and so it is difficult to obtain a highly precise and fine display type device and also it is difficult to obtain a large scale screen as the user desires; (2) it is not suitable for a multi-color display and is not applicable in sophisticated application fields, such as CAD/CAE (Computer Aided Design/Computer Aided Engineering).
Therefore, it is common to use, instead of the input integrated flat panel display alone, both the input integrated flat panel display and the highly precise and fine display type CRT for carrying out a subtle processing of handwritten characters or graphics. The reason for this is that the above problems can be solved at once by displaying a whole screen of data onto a highly precise and fine display type CRT display and by performing an input/output (display) operation, carried out for part of the whole screen (or for a partial screen), through an input integrated flat panel display.
With the system arrangement as mentioned above, a scrolling function for the input integrated flat panel display is indispensable in view of the display area and display resolution of the flat panel display. In addition, the man-machine performance is further improved if the apparatus is provided with a zooming function which changes the correspondence ratio between the display screens of the CRT display and the input integrated flat panel display. However, an input integrated flat panel display provided with scrolling and zooming functions has not yet been realized.
Conventional scrolling functions provided for a single display device other than an input integrated flat panel display are not convenient in use. That is, in general, instructions for scrolling are made by the operator by selecting and manipulating one of a plural buttons in accordance with the direction of scrolling the operator desires; the manipulation must be continued for the time proportional to the distance to be scrolled; and in order to set a desired direction for scrolling, a suitable combination of those buttons must be properly chosen. Furthermore, another system is known in which the coordinate input area and the scrolling instruction area are used in common and a mode change-over is necessitated. That is, in a scrolling instruction mode in such a system, a desired point is pointed to in order to display the corresponding area. Such system essentially requires a mode change-over so that the operations are cumbersome.
Further, apart from the problems described above, if the input integrated flat panel display can be used as one of the peripheral devices of a multipurpose personal computer and the like, it is possible to process handwritten characters or figures with ease and low cost by simply connecting the flat panel display to the conventional apparatus main frame. Thus, vast applications to not only professional users but also amateur end users are possible. In the case where the input integrated flat panel display is used as a peripheral device, since a typical personal computer or the like is provided as a display interface only with an interface (video signal line) for use in displaying on a CRT display, some modifications of the hardware of the personal computer main frame become necessary.
The present invention has been made in view of the above-mentioned prior art problems, particularly in view of the fact that the flat panel display serving as a display screen of an input integrated flat panel display has an insufficient display area and display resolution.